Virtual network system

ABSTRACT

A virtual wireless computer network allows communication between a number of regions (F, G, H), which may be beyond normal wireless communication range, by carrying information between regions using mobile stations ( 5 ) which travel between regions. Each mobile station transmits and/or receives information by wireless communication to other stations within a region when it is in that region, to update both the stations in that region and the mobile station. One region may include a fixed station ( 8 ) hardwired into a backbone network ( 9 ). The network has particular application in a mining situation where the mobile stations may be haul trucks ( 5 ) carrying information between people  6  and light vehicles ( 7 ), with the fixed station at a crusher or shovel ( 8 ).

FIELD OF THE INVENTION

This invention relates to a virtual wireless computer network and hasbeen devised particularly though not solely for use in a miningsituation.

BACKGROUND OF THE INVENTION

With the use of wireless computer technologies becoming more common,with accessible off-the-shelf systems now available in the market place,it has become known to create ad-hoc temporary dynamic networks. Underthe IEEE's proposed standard for wireless LANs (referred to throughoutthis specification as IEEE802.11x, being any of the IEEE802.11 wirelessnetworks), there are two different network configurations: ad-hoc andinfrastructure. In the ad-hoc network, computers are brought together toform a network in real time. FIG. 1 shows the structure of this networkwhere each element is potentially in contact with any other elementwithin the range in the network. Such virtual networks, when combinedwith fixed stations connected to a hard wired backbone can be used tomonitor or share information between different databases.

There are some situations however where individual ad-hoc networks maynot be in wireless range of one another and where it is impractical toprovide a wireless link or a hard wired backbone between the variousad-hoc networks. Such situations commonly exist in mining environmentswhere various groups of equipment are spaced apart a considerabledistance from one another or where their relationship changes as themining operation develops, in an environment where it is inconvenient ordifficult to provide hard wired connections.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a virtual wireless computernetwork including a plurality of stations arranged to interface witheach other by wireless communication in two or more regions, at leastone of said regions being beyond normal wireless communication range ofother said regions, and wherein at least one station is a mobile stationable to travel between regions, said mobile station being adapted toreceive and/or transmit information by wireless communication in oneregion when in that region, and receive and/or transmit information toother regions when in those regions.

Preferably one or more of the mobile stations is located in a vehicle.

Preferably one or more of the mobile stations is located on a personable to travel between regions.

Preferably at least one of the stations is hard wire connected to abackbone system.

Preferably the stations include slow moving stations primarily adaptedto be operating within regions, and fast moving stations primarilyintended to be moving between regions.

Preferably network is also adapted to be used as a safety alert systemproviding advice to the operator of a station of the presence of otherstations that may be in the immediate proximity.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms that may fall within its scope onepreferred form of the invention will now be described by way of exampleonly with reference to the accompanying drawings in which:

FIG. 1 is a schematic view of a typical prior art ad-hoc network;

FIG. 2 is a diagrammatic view of a decentralised network interactionaccording to the invention;

FIG. 3 is a diagrammatic view of a virtual wireless network according tothe invention in use in a typical mining operation;

FIG. 4 is a schematic view of an ad-hoc network according to theinvention used for detecting the proximity of other mobile stations to atruck;

FIG. 5 is a diagrammatic illustration of a typical computer box within amobile station such as a truck;

FIG. 6 is a view of a typical operator interface panel located within amining truck using information from the network according to theinvention; and

FIG. 7 is a schematic view of a moving haul truck showing intrudersapproaching the front of the truck;

FIG. 8 is a schematic view of a moving haul truck showing stationeryintruders in front of the truck;

FIG. 9 is a schematic view of a moving haul truck showing intruders infront of the truck and moving away from the truck;

FIG. 10 is a schematic view of a moving haul truck showing movingintruders approaching the rear of the truck; and

FIG. 11 is a schematic view of a moving haul truck approaching intrudersmoving in a direction perpendicular to the movement of the truck.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

It will be appreciated that although the virtual wireless computernetwork according to the invention has been devised particularly for usein a mining situation, it has broader uses and will firstly be describedin terms of a general decentralised virtual network.

The system is designed around independent stations or agents consistingof different types and with diverse capabilities in terms of processing,tasks and functionality. Different types of agents form various ad-hocnetworks that can be used to move information around areas much largerthan the wireless range. FIG. 2 presents some of the functionalities ofthe virtual network according to the invention. In this example we havethree types of agents: people 1 (slow moving local agents), fast/longrange moving agents 2 and fixed agents 3. The road or common areas wherethe fast agents move are also shown in long chain outline. In region orzone A an ad-hoc network 4 is formed with four slow moving agents and afast moving transport agent. This gives the capability of propagatinginformation from slow agents through the fast moving transport agent toother areas. This information can then be collected by a fixed agentconnected to the backbone system in zone B, and transferred anywhere inthe world almost in real-time. Zone C presents an ad-hoc network wherenot all the agents are in direct contact. Nevertheless with thisapproach agent M56 can have the information of agent M30 by using theother slow moving agents in between. The decentralized software enablesthe propagation of information to all the agents in the ad-hoc network.Region D presents the case of a fast moving agent moving information toa different destination. Finally zone E presents a local area with slowmoving agents interacting with information ready to transfer to otherregions.

In a specific application of the invention FIG. 3 shows the typicalinteraction of trucks 5, people 6, maintenance vehicles 7 and shovel 8in a mining environment. In this case each operator 6 has a PDA typedevice equipped with 802.11b capabilities and some can be retrofittedwith GPSs or other sensory information. The maintenance vehicle 7 willhave similar capabilities but different processing and storage media.

The virtual network concept introduced before can be used to transportinformation around the mine. In FIG. 3 an agent in the ad-hoc network Fcan transfer information to an agent truck 5 that is known to go to areaG where a fixed station Shovel 8 is available with connection to thebackbone network 9. The truck in G can also collect information withmine management directives from the backbone 9 to be delivered to otheragents in area H. With this concept a very efficient virtual network canbe built that connects all the operational areas of the mine withouthaving to have full wireless coverage of all the mine area. This isefficient since the mine will always concentrate the resources inparticular areas and these resources will be the ones that move with thenetwork. The area without add-hoc networks will not require attention(coverage) and will be traversed by the normal fast moving agents, suchas trucks 5.

Typically each agent will register itself in a ad-hoc 802.11x wirelessnetwork and will send a registering message reporting its owncapabilities, basic information and special requests. The possibleagents and some capabilities are shown in table 1 TABLE 1 Typicalproperties for an agent in a mining application Type Static/MobilePosition Range Other Person 1 (P1) M P Data Person 2 (P2) M R Vehicle(V1) M P R Data Vehicle (V2) M P Data Fixed Station F P R Data FixedStation F

The type of agents to interact in the environment are applicationdependant. For the case of a mining application we can define thefollowing agents ID Type Message type Information Destinations 10.0.1.10 Base station Data Data Places 10.0.1.30 1 Truck Position Data 1, 4, 510.0.1.100 2 Person Position Data 1

A full protocol is implemented to ensure that the information is movedsmoothly through the virtual network with integrity and at the same timewithout saturating the network in a local area. This protocol isimplemented on top of TCP/UDP libraries running in windows OS, QNXNeutrino and Power PC for PDAs

The network can also be used to provide a “Truck Safety Alert System”.

The objective of this system is to safely manage the interaction betweena truck and other objects in its environment (people, utility vehicles,etc) using the capabilities of the ad-hoc wireless network. The “TruckSafety Alert System” utilises a subset of the capabilities of theoverall system and provides a basic demonstration of its decentralizeddata transfer capabilities for a safety application.

A truck will know the position of each object in its safety zone bydirect communication with that object or through retransmission from aneighbour agent. If GPS is not available the system will report thepresence of that agent in the area of operation. This significantlyincreases the reliability of detection. Finally a two-way operationprotocol can be implemented where when the truck is about to move itinterrogates the agents in its safety zone.

A truck safety alert system of this type is necessary as drivers oflarge off-road haul trucks often cannot see objects (personnel, utilityvehicles, etc) in close proximity to the truck. The zone directly infront of the truck and the zone adjacent to the non-driver side of thetruck currently pose the greatest risk for an accident. These blindzones have been the cause of several haul truck/utility vehicleaccidents and near misses. Of particular concern is the ability of truckdrivers to verify that these zones are clear before pulling away from astationary position.

Several technologies have been proposed in the past to solve thisproblem, including:

GPS based systems—these require all mobile equipment and personnel topossess a GPS unit that communicates with a base station. This solutionis expensive, is not failsafe since it relies on each object having anoperational GPS unit, and complete GPS coverage in the pit (not alwayspossible).

RF ID tags—again this requires all mobile equipment and personnel towear a RF ID tag that will respond when in the truck proximity zone.There is at least one commercial system based on this approach but itonly provides indication that something is in the area. The detection ofthe location of the object using this technology requires additionalhardware and accuracy and cost may be an issue.

Video systems—this requires computer based image recognition of anobject in the proximity zone (which can be unreliable in varying lightconditions). Alternatively, this approach requires the driver to see theintrusive object in a small cab-mounted video screen that in poorlighting conditions can be un-reliable.

Radar/camera system, typically an operator aid system based on a Precoradar. The radar frequency is 5.8 GHz and can detect an object at rangesup to 8 meters within an arc of 55 degree horizontal and 20 degreesvertical. It is provided with hardware that interfaces the radar andprovides visual and audio alarm if an object is within the area. Thisoutput is then used to turn on the appropriate camera. Operators havenot been happy with this system due to the number of false alarmsprovided by the system

The present invention is able to provide a reliable system that informsthe driver of the presence of an unsafe condition in the area close tothe truck while not providing excessive number of false alarm. Areliable solution to this problem requires the use of multipleinformation sources and an appropriate inference engine to report to theoperator the state of unsafe objects in the area surrounding the truck.

The design uses a minimum number of sensors but still provides the basicstructure in order to augment the system to achieve high reliability andthe possibility to incorporate other safety and productivityenhancements.

The system is based on a computer box installed in each truck (truckcomputer) and all mine personnel and other mobile equipment carryingPDAs retrofitted with GPS, both with wireless capabilities (IEEE802.11x). FIG. 4 shows a temporary ad-hoc network formed by the truck 10and mobile devices 11. It can clearly be seen that although one of themobile devices 11A is not in direct contact with the truck, it is stillaware of its location through the neighbour information from 11B or 11C.This is one clear case where the network concept helps to make thesystem more reliable.

Each truck CPU Box has basic computer capabilities and an IEEE 802.11xwireless network interface to interface with the targets and serialinterfaces and digital/analog I/O for future expansion to differentsensing and monitoring capabilities. The basic box capabilities areshown in FIG. 5.

The Truck CPU is connected to an operator interface which reports to theoperator that there is a potential object in the area surrounding thetruck. If GPS is available and reported by the target an appropriate LED12 will be turn on to indicate the quadrant where the object is located.For example, LED 12A will illuminate when the object is in the quadrantto the front right (FR) of the truck as presented at 13. A sounder togenerate an audible alarm can also be installed in this box. Intelligentsensors with elementary bluetooth communication capabilities could beadded to improve the integrity of the system. Thus, If GPS is notavailable or if the mobile devices are not equipped with GPS, the systemwould still know what object (person, truck, etc) is in its “zone” butnot its exact location. The operator box is shown in FIG. 6.

The equipment that is typically carried by slow moving stations oragents such as personnel in the mine is designed around hand held PDA'swith built in IEEE 802.11x wireless capabilities. The handheld will alsohave in most cases built-in GPS and Bluetooth capabilities. Utilityvehicles used by maintenance, supervisory and engineering staff arebased around industrial laptop/type units containing IEEE 802.11xwireless, GPS and Bluetooth capabilities. This allows the independentinstallation of the two devices, for example the GPS in the operator'shelmet and the PDA in the operator's pocket without the need of wiringto join each other.

FIG. 4 shows a haul truck vehicle and a number of targets around it thataxe communicating through the wireless link IEEE 802.11x. Thiscapability opens up a number of possibilities to improve safety. Thisimplementation of a two way communication system, is an enablingtechnology that allows safety interlock procedures to be implementedbefore moving a truck when other objects are in its zone. For examplethe driver can issue a request to start and a target in the area candeny this authorisation if a collision risk exists.

In a more sophisticated version of the proximity detection systemdescribed above, the velocity of both the haul truck vehicle and thesurrounding mobile devices is taken into account. Although this systemrequires GPS to provide position fixes and velocity vectors, it onlyrequires a standard GPS solution. The standard GPS solution onlyrequires three satellites in view to operate and this is available inmost open pit mines.

Each agent is equipped with GPS and broadcasts its position andvelocity. The haul truck proximity system can then generate a differenttype of alarm according to the threat level, e.g. truck approaching infront, vehicle behind etc.

Although the system has capabilities to detect all these situations, theoperator reporting capabilities will be very demanding in the situationshown in FIG. 7 where the truck 13 is moving forward as indicated byvector 14 and one or more “intruders” 15 are coming at the front of thetruck.

In this situation, a high level alarm can be generated to warn the truckoperator of the immediate impending danger.

In other situations alarms may be generated at different levels. Forexample in the situation shown in FIG. 8 where the truck 13 is movingforward as shown by vector 14 but the intruders 16 are not moving, thealarm may not be triggered until the intruders enter the warning areadefined by dotted line 17. A similar situation could apply as shown inFIG. 9 where the truck is moving forward as before but the intruders 18are at the front of the truck and moving in the same direction.

FIG. 10 shows yet another variation where the truck is moving forwardbut intruders 19 are approaching the truck from behind at velocities 20greater than the velocity 14 of the truck 13. In situations like this,it may be desirable to have a separate danger area 21 defined inside thewarning area 17 to alert the operator of the truck at different levelsof danger as the intruder moves from the warning area into the dangerarea 21.

A further situation is shown in FIG. 11 where the intruders 22 may be atthe front of the truck moving in a perpendicular direction. Again, thedegree of warning provided to the truck operator may be tailored to theindividual situation so that different levels of light and soundwarnings can be provided to suit the degree of danger and the immediacyof the problem facing the truck operator.

In this manner a mine wide virtual wireless system is providedconsisting of wireless nodes or stations (CPU, wireless capabilities,network capabilities, GPS, etc., mounted on mobile equipment and fixedbase stations) linked together in a decentralized network. The systemimplements a flexible network backbone using mobile vehicles (such atrucks) that follow regular paths between load and dump locations. Othermobile and fixed nodes will interface with this data highway(transporting data to and from the central server) and can receive,transport and transmitted data collected from nodes that are more remotefrom the data highway. This system also provides the capability forpersonnel (supervisors, engineers, etc) operating in the mine to accesssystems on-board mobile equipment without the need to climb on-board.This capability to download data in the field from on-board systems inorder to monitor productivity/reliability, etc., or upload new machineand operator tasks or settings, has the potential to change the waymines manage mobile equipment.

1-12. (canceled)
 13. A virtual wireless computer network including aplurality of stations arranged to interface with each other by wirelesscommunication in two or more regions, at least one of said regions beingbeyond normal wireless communication range of other said regions, andwherein at least one station is a mobile station able to travel betweenregions, said mobile station being adapted to receive and/or transmitinformation by wireless communication in one region when in that region,and receive and/or transmit information to other regions when in thoseregions.
 14. A virtual wireless computer network as claimed in claim 13,wherein one or more of the mobile stations is located in a vehicle. 15.A virtual wireless computer network as claimed in claim 13, wherein oneor more of the mobile stations is located on a person able to travelbetween regions.
 16. A virtual wireless computer network as claimed inclaim 13, wherein at least one of the stations is hard wire connected toa backbone system.
 17. A virtual wireless computer network as claimed inclaim 13, wherein the stations include slow moving stations primarilyadapted to be operating within regions, and fast moving stationsprimarily intended to be moving between regions.
 18. A virtual wirelesscomputer network as claimed in claim 13, wherein the network is alsoadapted to be used as a safety alert system providing advice to theoperator of a station of the presence of other stations that may be inthe immediate proximity.
 19. A virtual wireless computer network asclaimed in claim 18, wherein the velocities of each of the stations aretaken into account and a warning given to the operator appropriate tothe danger detected.
 20. A virtual wireless computer network as claimedin claim 19, when provided to the operator of an oversize off-road haultruck and wherein both the velocity of the haul truck, and the positionand velocity of any potential intruders in the vicinity of the haultruck are taken into consideration.
 21. A method of communicatinginformation comprising the steps of providing a virtual wireless networkas claimed in claim 13, and using that network to transfer informationbetween regions.
 22. A method as claimed in claim 21 when used in amining environment.